First encounter with the atomic concept (1919-1920) -- The decision to study physics (1920) -- "Understanding" in modern physics (1920-1922) -- Lessons in politics and history (1922-1924) -- Quantum mechanics and a talk with Einstein (1925-1926) -- Fresh fields (1926-1927) -- Science and religion (1927) -- Atomic physics and pragmatism (1929) -- The relationship between biology, physics and chemistry (1930-1932) -- Quantum mechanics and Kantian philosophy (1930-1934) -- Discussions about language (1933) -- Revolution and university life (1933) -- Atomic power and elementary particles (1935-1937) -- Individual behavior in the face of political disaster (1937-1941) -- Toward a new beginning (1941-1945) -- The responsibility of the scientist (1945-1950) -- Positivism, metaphysics and religion (1952) -- Scientific and political disputes (1956-1957) -- The unified field theory (1957-1958) -- Elementary particles and platonic philosophy (1961-1965)